It's about one-and-one-tenth times as fast as a Fastball (baseball).
In other words, the speed of a Fastball (baseball) is 0.910 times 86.90 knots.(a.k.a. rising fastball, a.k.a. cross-seam fastball, a.k.a. heater, a.k.a. hummer, a.k.a. smoker; for four-seam grip) (major league average)
The average speed of major league fastball pitch is 81 knots. When up against the quickest professional fastball pitchers, a batter may have less than 0.4 seconds to react to a pitched ball.
It's about four-fifths as fast as a Skydiver (belly-to-earth).
In other words, 86.90 knots is 0.840 times the speed of a Skydiver (belly-to-earth), and the speed of a Skydiver (belly-to-earth) is 1.20 times that amount.(Belly-to-Earth orientation, average conditions, terminal velocity)
A belly-to-Earth oriented skydiver's terminal velocity is about 100 knots. In a typical jump from 3,900 m (13,000 ft), a diver in this orientation will be in freefall for 60 seconds.
It's about four-fifths as fast as a Tornado.
In other words, 86.90 knots is 0.80973870 times the speed of a Tornado, and the speed of a Tornado is 1.2349660 times that amount.(EF2) (wind speed range average)
According to the Enhanced Fujita scale implemented by the US National Oceanographic and Atmospheric Administration, a "significant" tornado has an Enhanced Funjita scale classification of EF2 and is characterized by wind gust speeds between 95.587390 knots and 119.0497 knots. The largest recorded tornado — an F4 event occurring in Nebraska in May, 2004 — was almost 4.02 km (2.5 mi) across.
It's about one-and-three-tenths times as fast as a Curveball (baseball).
In other words, the speed of a Curveball (baseball) is 0.770 times 86.90 knots.(a.k.a. hook, a.k.a. hammer, a.k.a. yakker) (major league average)
The average speed of major league curveball pitch is 65 knots. In the 1940's, debate over whether there really was a curve in the curveball pitch was settled with the conclusion that the ball does curve; however, an optical illusion caused by the spin of the ball and the batter's perception of motion exaggerates the extent of the curve.
It's about one-and-one-third times as fast as a Hurricane.
In other words, the speed of a Hurricane is 0.7410 times 86.90 knots.(formally: Topical cyclone; a.k.a. typhoon)
A hurricane is defined by the US National Hurricane Center as a Northern Hemisphere tropical storm having one-minute average wind-speeds of at least 64.30 knots. Typhoons Tip (October, 1979) and Keith (October, 1997) and Hurricanes Camille (August, 1969) and Allen (August, 1980) jointly hold the record for highest tropical storm wind speeds at 167 knots.
It's about one-and-a-half times as fast as a Cheetah.
It's about one-and-a-half times as fast as a Knuckleball (baseball).
In other words, the speed of a Knuckleball (baseball) is 0.670 times 86.90 knots.(a.k.a. knuckler, a.k.a. floater, a.k.a. dancer, a.k.a. butterfly ball) (major league average)
The average speed of major league knuckleball pitch is 59 knots. Eddie Cicotte, who was later implicated in the 1919 Black Sox scandal, is credited with developing the pitch ca. 1906.